THE BASICS OF JEWELRY - PART 2

What Determines Value in Colored Gems?
Color is the single most important determinant of value in colored stones. Second most important is cut, which maximizes the gemstone's life and brilliance. Generally, the more a gemstone approximates its pure spectral color, the more desirable it is. And the better the cut, the better the depth of color and the liveliness of the stone.

There are numerous other characteristics that contribute to the quality and value of colored gems. These include:

Brilliance - The intensity with which a stone catches the light and displays life.
Beauty - How it enhances one's appearance - closely related to its color.
Durability - The stone's ability, when set in jewelry, to withstand normal wear.
Rarity - The available supply. The harder to get, the more it costs.
Demand - High demand may overshadow other factors and drive up a gem's price.
Tradition - Using gems for adornment, symbolism or as a means of exchange.
Portability - In times of turmoil, gems are an investment that can be readily moved.

More color cues
Color is affected by a number of variables. It is primarily affected by light - both the type and the intensity. And clearly, color is a very subjective matter in terms of what is considered attractive and desirable. The best approach (and ours at Shane Co.) is combining the eye and the brain - along with years of experience in the colored-stone business.

Describing Color
Generally, the closer a colored stone comes to being the pure spectral hue of that color, the better the color and the more valued the stone. The spectral colors (remember the rainbow?) go from pure red to pure violet. They don't include white, black, gray or brown, but these colors affect the tone of color seen, and ultimately the grading.

Factors commonly used to describe color:
Hue - the precise spectral color
Intensity - the brightness or vividness
Tone - the lightness or darkness
Distribution - the consistency or evenness of color distribution
Saturation - the depth and richness of color

Also consider that:
A good lapidary (gem cutter) who optimizes the proportions of the cut brings out a fine stone's maximum intensity and color, making it very desirable. A poor cut significantly reduces the stone's vividness and depth of color.

In general, gemstones that are either very light (pale) or very dark sell for less per carat. For example, a rich, deep color is desirable, but you don't want it to approach black.

A stone's color can appear to change depending on the kind of light and the environment in which you're viewing it. For example, a ruby will not look as red under fluorescent lighting as it will under ordinary incandescent lights or daylight.

In colored stones, the color may not always be evenly distributed throughout the stone, but instead exist in zones, layers or spots, giving the appearance of color in areas of the stone that are actually colorless. This is sometimes observed in amethyst, ruby and sapphire. The evenness and complete saturation of color will greatly affect the value of a colored gem.

Clarity
As with diamonds, clarity refers to the stone's purity or absence of internal inclusions (tiny spots, fractures or anything trapped within the crystal). However, while clarity is important, there is less expectation for a colored stone to be free of natural markings. Depending on the type of gemstone, the absence of inclusions can be even more rare than a flawless diamond - and command a higher cost per carat. It really varies with the gemstone: an emerald will always have inclusions, but a blue topaz should be very clear.

The lighter the stone, the more visible inclusions will be. In a darker stone, they may be masked by deeper color, and thus matter less. Of greater concern in colored gems is the type and placement of inclusions. A large crack (called a feather) near the surface of a stone makes it less durable and disrupts the play of light, detracting from the value. But a small, unobtrusive fracture will have minimal effect on the gem's durability, beauty and value. And some natural markings can be desirable to the degree that they validate the origin or variety of the stone.

Importance of Cut
Cut and proportion in colored stones impacts the depth of color seen in the stone and the liveliness projected by the stone. Unlike diamonds, there is no "ideal cut" for colored stones. They are cut to maximize weight recovery and consistency of color from the rough crystal. Also, while cut is important for any gemstone, the criteria for judging cut quality in colored stones and diamonds is quite different. Oftentimes the proportions needed to produce the best color in a stone would be considered quite poor if that stone were a diamond.

Weight, Size and Density
All gems are priced by the carat, except pearls and coral. Normally the greater the weight, the greater the value per carat (under 50 carats) However, certain stones, such as amethyst, garnet, and topaz, become less valuable per carat if they are so big they cannot be mounted. Also, weight and size are not the same thing. Some stones weigh more than others, as the density (specific gravity) of the basic mineral is heavier. Consider:

Rubies and sapphires weigh 20% more than diamonds.
Emeralds weigh 20% less than diamonds.
If a diamond weighs 1.00 carat, the same size ruby or sapphire would weight approximately 1.20 carats, and the same size emerald would weigh approximately .80 carat.

Also consider that some stones are readily available in large sizes while others are not. Scarcity of particular sizes among the different colored stones will dictate what is considered "large" in the market, affecting price. Like diamonds, colored stones of less than one carat sell for less per carat than stones of a full carat or more. But again, what's considered "large" or "rare" differs with the stone.

Colored stones are actually measured in the industry by dimensions in millimeters in addition to carat weight. Millimeter size of the stone often matters more - especially in matching colored stones for a ring, earrings, or other types of jewelry.

In short, when evaluating a colored gem for purchase, ask yourself:

Is the shade of color attractive?
Does the stone have brilliance and life?
Is the color too dark or too light?
Is the stone uniformly brilliant, or does it have "flat" areas with no life?
Overall, does it appeal to you?

We hope that our basic guide could help you to understand the basics of jewelry. If you still have more questions, please contact us by clicking here. Thank you for your time.


 

© 2001 by HubertGem.com   -   info@hubertgem.com   -   Toll Free: 1-866-HUBERTS